Polysomnography is a sleep study. A sleep study monitors you as you sleep, or try to sleep.
There are two states of sleep:
REM sleep is associated with dreaming. Your body muscles (except your eyes and lungs) do not move during this stage of sleep.
NREM sleep has four stages that can be detected by EEG waves.
REM sleep alternates with NREM sleep approximately every 90 minutes. A person with normal sleep usually has four to five cycles of REM and NREM sleep during a night.
A sleep study measures your sleep cycles and stages by recording the following information:
Sleep study; Polysomnogram; Rapid eye movement studies
How the test is performedThe most common type of sleep study is performed at a special sleep center. You will be asked to arrive about 2 hours before bedtime. You will sleep in a bed at the center. Many sleep centers have rooms that are similar to hotel rooms, so that you are in a comfortable bedroom. The test is often done during the night so that your normal sleep patterns can be studied.
The health care provider will place electrodes on your chin, scalp, and the outer edge of your eyelids. These must remain in place while you sleep.
Signals from electrodes are recorded while you are awake (with your eyes closed) and during sleep. The time it takes you to fall asleep is measured, as well as the time it takes you to enter REM sleep.
Monitors to record your heart rate and breathing will be attached to your chest. These also must remain in place while you sleep. A specially trained health care provider will directly observe you while you sleep and note any changes in your breathing or heart rate. The number of times that you either stop breathing or almost stop breathing will be measured.
In some sleep study centers, a video camera records your movements during sleep.
How to prepare for the testDo not take any sleeping medication and do not drink alcohol or caffeine-containing beverages before the test.
Why the test is performedThe test is done to diagnose possible sleep disorders, including:
A normal test result shows usual or normal patterns of brain waves and muscle movements during sleep, without frequent breathing problems.
What abnormal results meanAbnormal results may confirm a suspected sleep disorder. For example, episodes of stopped breathing during sleep is called sleep apnea.
ReferencesCollop NA, Anderson WM, Boehlecke B, Claman D, Goldberg R, Gottlieb DJ, et al. Clinical guidelines for the use of unattended portable monitors in the diagnosis of obstructive sleep apnea in adult patients. Portable Monitoring Task Force of the American Academy of Sleep Medicine. J Clin Sleep Med. 2007 Dec 15;3(7):737-47.
Ahmed M, Patel NP, Rosen I. Portable monitors in the diagnosis of obstructive sleep apnea. Chest. 2007 Nov;132(5):1672-7.
Patel NP, Ahmed M, Rosen I. Split-night polysomnography. Chest. 2007 Nov;132(5):1664-71.
Patil SP, Schneider H, Schwartz AR, Smith PL. Adult obstructive sleep apnea: pathophysiology and diagnosis. Chest. 2007 Jul;132(1):325-37.
Polysomnography is a sleep study. A sleep study monitors you as you sleep, or try to sleep.
There are two states of sleep:
REM sleep alternates with NREM sleep about every 90 minutes. A person with normal sleep usually has four to five cycles of REM and NREM sleep during a night.
A sleep study measures your sleep cycles and stages by recording:
Sleep study; Polysomnogram; Rapid eye movement studies; Split night polysomnography; PSG
How the test is performedAT A SLEEP CENTER
The most common type of sleep study is performed at a special sleep center. You will be asked to arrive about 2 hours before bedtime. You will sleep in a bed at the center.
Many sleep centers have rooms that are similar to hotel rooms, so that you are in a comfortable bedroom. The test is often done during the night so that your normal sleep patterns can be studied.
The health care provider will place electrodes on your chin, scalp, and the outer edge of your eyelids. These must remain in place while you sleep.
Signals from the electrodes are recorded while you are awake (with your eyes closed) and during sleep. The time it takes you to fall asleep is measured, as well as the time it takes you to enter REM sleep.
Monitors to record your heart rate and breathing will be attached to your chest. These also must stay in place while you sleep. A specially trained health care provider will observe you while you sleep and note any changes in your breathing or heart rate. The number of times that you either stop breathing or almost stop breathing will be measured.
In some sleep study centers, a video camera records your movements during sleep.
AT HOME
Portable sleep study devices that can be used in the home instead of at a sleep center are available to help diagnose sleep apnea. You go to a sleep center to pick up the device, or a trained therapist comes to your home to set up the device.
Portable devices are best used when:
Do not take any sleep medicine and do not drink alcohol or caffeinated beverages before the test.
Why the test is performedThe test is done to diagnose possible sleep disorders, including obstructive sleep apnea (OSA). Often, OSA is suspected because of the following symptoms:
Other sleep disorders that polysomnography may be used to diagnose are:
A sleep study keeps track of:
Results are most often reported using the Apnea-Hypopnea Index (AHI). An AHI of less than 5 is considered normal.
A normal test result also shows normal patterns of brain waves and muscle movements during sleep.
What abnormal results meanApnea-Hypopnea Index (AHI) results are used to diagnose obstructive sleep apnea.
The sleep specialist must also look at other findings from the sleep study, as well as the medical history and physical exam to make the diagnosis and decide on treatment. A sleep study can also help diagnose narcolepsy.
ReferencesSkomro RP, Gjevre J, Reid J, et al. Outcomes of home-based diagnosis and treatment of obstructive sleep apnea. Chest. 2010;138:257-263.
Tice JA. Portable devices used for home testing in obstructive sleep apnea. California Technology Assessment Forum. March 11, 2009. Accessed June 9, 2010.
Collop NA, Anderson WM, Boehlecke B, et al. Clinical guidelines for the use of unattended portable monitors in the diagnosis of obstructive sleep apnea in adult patients. Portable Monitoring Task Force of the American Academy of Sleep Medicine. J Clin Sleep Med. 2007;3:737-747.
Epstein LJ, Kristo D, Strollo PJ Jr. Adult Obstructive Sleep Apnea Task Force of the American Academy of Sleep Medicine. Clinical guideline for the evaluation, management, and long-term care of obstructive sleep apnea in adults. J Clin Sleep Med. 2009;5:263-276.
Cao M. Advances in narcolepsy. Med Clin N Am. 2010;94:541-555.
Reviewed ByReview Date: 07/31/2011
Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Polysomnography is extremely safe and no special precautions need to be taken.
Polysomnography-- A group of tests administered to analyze heart, blood, and breathing patterns during sleep.
Once the test is over, the monitors are detached from the patient. No special measures need to be taken after polysomnography.
Polysomnography-- A technique for diagnosing sleep disorders with the use of a machine that records the pulse, breathing rate and other variables while the patient sleeps.
Polysomnography
Polysomnography
polysomnography
Without insurance, lab-based polysomnography cost approximately $1,500 in 1997, while overnight home monitoring cost between $500 and $1,000.
The study of sleep is called polysomnography.
The polysomnography study includes measurements of heart rate, airflow at the mouth and nose, respiratory effort, sleep stage (light sleep, deep sleep, dream sleep, etc.), and oxygen level in the blood.
A normal result in polysomnography shows normal results for all parameters (EEG, ECG, blood pressure, eye movement, air flow, pulse oximetry, etc.) monitored throughout all stages of sleep.
No you do not need a license in Pennsylvania as of now but licensure is in the works.